Peripheral blood circulating immature cell counts predict CD34+ cell yields in G-CSF-induced PBPC mobilization in healthy donors

BACKGROUND: It has been previously reported that the number of circulating immature cells (CIC) in peripheral blood (PB) estimates the number of CD34+ cells collected in G-CSF plus chemotherapy-induced PBPC mobilization. The correlation of CIC counts in PB with CD34+ cell yield and its usefulness was evaluated in G-CSF-induced PBPC mobilization for healthy donors. STUDY DESIGN AND METHODS: CIC counts in PB and CD34+ cell counts in the apheresis product from 122 collections were assessed, and the relationship between these two variables was evaluated with the Pearson rank correlation analysis, the chi-squared test, and the U-test. RESULTS: CIC counts were correlated weakly with the number of CD34+ cells per L of blood processed in the apheresis product (Pearson rank correlation analysis; r = 0.357, p < 0.0001). When a level of 1.7 x 109 CICs per L was selected as a cutoff value, the sensitivity and specificity for collecting more than 20 × 10⁶ CD34+ cells per L of blood processed were 63.6 and 77.5 percent, respectively. CONCLUSION: The present study suggests that the number of CICs in PB may estimate the number of CD34+ cells collected. The data indicate that CIC counts above 1.7 × 10⁹ per L can be used as a good predictor for PBPC collections containing more than 20 × 10⁶ CD34+ cells per L of blood processed in a single apheresis procedure.